Die clamp



May 16, 1961 G. M. SUMMER ETAL INVENToRs.- G ON M. SOMMER TH DORE J. TERMEER BY May 16, A1961 G. M. SOMMER ETAL 2,984,176

DIE CLAMP Filed May 15, 1957 4 Sheets-Sheet 2 INVENToRs.- GORDON M. SOMMER THEODORE J. TERMEER ATTYS May IG, 1961 G. M. SOMMER HAL 2,984,176

DIE CLAMP Filed May 15. 195'? 4 sheets-sneet :s

(D ID INVENTORS.' GORDON M. SOMMER THEOOORE J. TERMEER BY www@ FIG. 5

May 16, 1961 Filed May 15. 1957 FIGS INVENTORS: GORDON M SOMMER TH EODORE J. TERMEER United States Patent O i DIE CLAMP Gordon M. Sommer, Hinsdale, and 'I'heodore J. Ter Meer, La Grange, Ill., assiguors to U.S. Industries, Inc., New York, N.Y., a corporation of Delaware Filed May 15, 1957, Ser. No. 659,259

3 Claims. (Cl. 10U-295) This invention relates in `general to a device for clamping a pair of members together, and more particularly to aV clamping device `for clamping a die to a movable slide of a press.

With the advent of new and advanced manufacturing methods and apparatuses to obtain greater production, it has been found necessary in the field of metal working presses to increase the production of these presses in accordance with the demands of industry. One of the ways to increase the production of a press is to reduce the time of shutting down the press for changing of the die. This has been accomplished by constructing a press having movable bolsters, wherein the dies maybe positioned on one bolster while the machine is in operation with the other bolster. In such an arrangement, the lower die would be secured to the movable bolster so that changing of the die by moving one bolster out of the press and another into the press would necessitate quick connection and disconnection of the upper die to the slide. Thus, shut down time during changing of the dies may be materially reduced thereby increasing production of the press.

The present invention provides a device for quickly clamping 4or unclamping the upper die to the movable slide, although other uses `and purposes will be apparent Y to one skilled in the art.

Accordingly, it is an object of this invention to provide a device for clamping a pair of members together.

Another object of this invention resides in the provision of quickly and easily clamping or unclamping an upper die to a movable slide of a metal working press.

Still another object of this invention is in the provision of a die clamp for tightly securing the upper die of a die set to a movable slide in a metal working press, wherein the die clamp may be remotely controlled.

A further object of this invention is to provide a clamping device operated by an actuating means, wherein if the actuating means fails, the clamping device will not unlock and permit disconnection between its clamped parts.

A still further object of this inventionV is in the provision of a die clamp for clamping a die to a movable slide of a metal working press which includes an eccentric arrangement whereby very little movement in an actuating member may cause clamping or unclamping action of the die clamp to clamp or release the die from the movable slide.

Another object of this invention is to provide a die clamp that is hydraulically operated, wherein if the hydraulic pressure fails, friction in the device maintains it in a self-locking position and if the friction were decreased, a. second means is provided to prevent the clamping device from swinging to an unclamping position relative to the die and slide.

Other objects, features, and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings. wherein like reference numerals refer to like parts, in which:

Fig, 1` is a fragmentaryKv and partially sectional view Patented May 16, 1961 fo 1C@ of a slide in a press and a die clamped together by an embodiment of the present invention;

Fig. 2 is a view similar to Fig. l but showing the members in unclamped position;

Fig. 3 is a greatly enlarged view of ther die clamp according to the invention, taken substantially along line 3 3 of Fig. l;

Fig. 4 is a partially sectional and elevational view of gie die clamp, taken 'substantially along line 4-4 of Fig. 5 is a vertical sectional view taken through the clamp of the present invention and showing the slide and die in section, and illustrating the parts of the die clamp in the clamped position;

Fig. 6 is a view similar to Fig. 5 but showing the clamping bolt in unclamped position and the parts associated therewith;

Fig. 7 is a view lsimilar to Fig. 6 but showing the clamping bolt swung outwardly to disengaged position relative to the upper die;

Fig. 8 is a fragmentary side elevational View of a slide and die showing the mounting of a pair of die clamps according to the invention and in clamped position relative to the associated parts; and

Fig. 9 is a perspective view, with certain parts cut away to show underlying parts and some parts in section of the die clamp of the present invention.

Referring toV the drawings, the clamping device or die clamp, generally indicated by the numerall 10, Figs. l and 2, is illustrated as being utilized to clamp an upper die or punch 11 `to a slide '12 of a metal working press, although it will be appreciated that this clamping device may be similarly applied for the purpose of quick clamp A or quick release of any two or more members. It may be further noted in connection with Figs. l, 2, and 8 that a plurality of die clamps 10 are generally provided to clamp the die to the slide, and in this instance, four in number, although 4any number may be utilized depending generally upon the size of the press structure. Fig. l illustrates the die clamps in clamped position whereby the die is tightly locked or clamped to the slide, while Fig. 2 illustrates the clamping dies in unclamped position so that the die 11 may be released from the slide 12.

Generally, the die clamps may be mounted as seen in Figs. l, 2, and 8 wherein the die cla-mp is mounted on an outwardly projecting flange 13 of the slide. slide and flange may be provided with the usual type of T-slots 14 for mounting a die in the conventional fashion with the use of T-bolts, although the present invention provides a quick clamping or releasing action of the die relative to the slide.

Each die clamp 10` includes generally a'support bracket 15, an eccentric shaft 16 bearingly mounted in the support bracket, a double-acting Huid or hydraulic cylinder 17 for reciprocably rotating the shaft 16, a yoke 18 pivotally suspended from the eccentric shaft, and a clamping bolt or locking arm 19 adjustably carried by the yoke.

Referring now more particularly to Figs. 3 to 9, it is seen that the support bracket 15 includes parallel spaced vertical bars 20 and 21 of substantially triangular shape. As seen particularly in Figs. 3 and 9, the bar 20 is provided with upper and lower inwardly extending bosses 22 and 23, respectively, while the other bar- 21 is provided with inwardly extending upper and lower bosses 24 and 25, respectively( The upper bosses 22 and 24 are arranged on the front or outside of the bar 20 and 21, while the lower bosses 23 and 25 are arranged on the inside or rear side of the bars and the bosses are provided with aligned bores for respectively receiving nut and bolt assemblies 26 and 27 to bring the bosses tightlytogether in intimate relationship thereby exactly spacing the bars 20 and. 21 at. a desired distance apart. To further hold This upper l the bars together, the front and bottom ends of the bars 20 and 21 are apertured to receive a nut and bolt assembly 28 as seen most clearly in Figs. 8 and 9.

So that the die clamps may be rigidly mounted on the ange 13 of the upper die 12, vertically arranged mounting ears 29 and 30 extend laterally from the outer sides of the bars 20 and 21 at the lower end thereof, Figs. 3, 5, 8, and 9. These ears are provided with vertical bores for receiving nut and bolt assemblies or fasteners 31 and 32 which secure the support brackets of the die clamps rigidly to the flange 13 of the slide 12.

Each bar of the support bracket is provided with a mounted sleeve bearing or bushing 33 which rotatably receives in bearing engagement bearing portions `34 of the eccentric shaft 16. Midway between the ends of the eccentric shaft 16 is secured a bifurcated member defining control arms 35 which may be suitably connected to a drive means for rotating the eccentric shaft through the desired arcuate path of movement. Inasmuch as the operation of the die clamp depends upon reciprocation of the eccentric shaft 16, it is necessary to impart a reciprocating motion to the control arm in operating the die clamp by means of manual or mechanical means.

Preferably, as illustrated with the invention, a doubleacting hydraulic cylinder 17, including a cylinder 36 pivoted at one end to the upper end of the bars 20 and 21 by means of trunnions 37 on the cylindery and bosses 38 with aligned bores, and a piston rod 39, serves to impart the necesary reciprocatory motion to the control arms 35 of the eccentric shaft 16. The outer end of the piston rod 39 is received between the control arms 35 and connected thereto pivotally by a pin 40. Hydraulic fluid may be selectively supplied to the opposite ends of the cylinder 36 selectively through the uid lines 41 and 42, Fig. 9 by any suitable source.

Referring again to Figs. 4 and 9, it is seen that a pair of eccentrics 43 and 44 are axially spaced on the eccentric shaft 16 and arranged on opposite sides of the control arms 35. Effectively, the eccentric shaft 16 therefore includes the bearing portions 34, the control arms 35, and the eccentrics 43 and 44, all connected together or integral to operate as an integral unit. The center line of the eccentrics aligns with the pivots of the piston rod and the control arms, that is, with the axis of the control arms 3S, the center line extending through the high point of the eccentric. Thus, it is seen that the eccentrics 43 and 44 on the eccentric shaft 16 are reciprocated through an arcuate path by the doubleacting hydraulic cylinder 17.

The yoke 18 is bearingly carried by the eccentric of the eccentric shaft, and the yoke includes a pair of identically shaped split parts 45 and 46, Fig. 4. The part 45 comprises an upper annular portion or strap 47 fitted with a sleeve bearing or bushing 48 which bearingly receives the eccentric 43, and a lower semi-circular portion 49 having an axis normal to the annular portion 47. Similarly, the part 46 includes an annular portion or strap 50 fitted with a sleeve bearing or bushing 51 and a lower semi-circular portion 52. The split yoke parts 45 and 46 are held together by front and back nut and bolt assemblies 53, and the semi-circular portions 49 and 52. are internally threaded to threadedly receive the upper threaded end of the clamping bolt 19. In order to normally bias the clamping bolt 19 into position as seen in Fig. 6, springs 54 and 55 engage on one end projections 56 and 57, respectively, of the annular portions 47 and 50 of the yoke parts and at the other end against the bosses 25 and 23 of the support bracket `15. Pins are carried by the projections to receive thereover the springs and maintain them in properly guided arrangement with respect to the bosses 25 and 23.

The lower free end of the clamping bolt 19 is provided with an enlarged head 58, circular in form, which bears against the underside of a ange 59 formed on 4. the die or punch 11. To further accommodate mounting of the die clamp on the slide 12 and for operation in connection with the die 11, aligned slots 60 and 61 are provided in the slide and die, respectively so that the clamping bolt may be swung outwardly or inwardly depending whether or not the die clamp is operated to release the die 11 from the slide 12 or to tightly clamp the die t0 the slide. Should it be desired to adjust the positioningV of the head 58 of the clamping bolt to a certain spacing between it and the flange 13 of the slide or the bottom end of the support bracket bars 20 and 21, the outer or front bolt 53 of the yoke 18 may be released, and a wrench may be applied to the flatted portions 62, 62 of the clamping bolt to rotate it in either direction so that the threads may adjust the positioning of the head 58 as desired.

In operation, when it is desired to release the die 11 from the slide 12, the die clamp 10 having its components positioned as seen in Fig. 5, the hydraulic cylinder 17 is actuated to stroke the piston rod 39 downward and thereby rotate the eccentric shaft and eccentrics 43 and 44 by means of the control arms 35 to thereby drop the clamping bolt 19 and free it from the lower die 11 as seen in Fig. 46. Further downward stroke of the hydraulic cylinder 17 causes further rotation of the eccentric shaft 16 whereby the piston rod and control arms engage the yoke 18 as seen in Figs. 6 and 7 to force the clamping bolt 19 outwardly to a position in Fig. 7 against the biasing of the springs 54 and 55. Thus, when all of the clamp dies 10 are so actuated, the die is completely released from the slide so that it may be moved out and thereby permit another die to be moved into its place for connection to the slide.

In clamping the die and slide together, the cylinder reverses its cycle to provide the upward stroke of the piston rod 39 and move the eccentric shaft 16 to the position as shown in Fig. 6. Due to the biasing of the springs 54 and 55, the yoke 18 will swing the clamping bolt 19 into position as seen in Fig. 6, and further stroking of the cylinder 17 will then rotate the eccentrics 43 and 44 relative to the yoke 18 which cannot be rotated any further due to its abutting against the lower bosses 23 and 25 and thereby draws the bolt 19 upwardly to the position'shown in Fig. 5 Vto tightly clamp the lower die 11 to the slide 12. When fully clamped as seen in Fig. 5, the friction of the movable hydraulic cylinder and eccentric shaft and associated partsis such that if the hydraulic pressure fails, the eccentric will not rotate by itself to release the clamping bolt, and therefore may be considered as self-locking. yEven if the bolts were moved a suicient amount to unlock them with respect to the die, the springs 54 and 55 would prevent the clamping bolt from swinging outwardly. Accordingly, double safety features are embodied in this clamp die. After the die is lirmly clamped, final shutheight adjustments may be made with the air of micrometer readings on the slide adjustment in the usual manner.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

l. In a press having a movable slide and a die mountable thereon, a die clamp for clamping the die to said slide, said die clamp comprising, a support bracket including a pair of parallel bars mounted on said slide, a shaft journalled on said bars, a pair of control arms mounted on and extending from said shaft, a hydraulic cylinder having a piston rod pivotally connected to said control arms, an eccentric carried on said shaft and positioned between said bars, said eccentric being positioned relative to the pivot connection of said piston rod and control arms so that the high point of the eccentric substantially aligns with a plane extending through the axis of 'said shaft and said pivot connection and is positioned therebetween, a clamping bolt having a strap on one end thereof carried by said eccentric and lockably engageable with said die whereby when said bolt is locking said slide and die together actuation of said cylinder in one direction rotates said shaftA and eccentric to move the bolt away from the shaft and initially unlock the clamp and further actuation causes the control arms to swing the clamping bolt outward from the die, and means for normally biasing said clamping bolt into engagement with said slide.

2. In a press having a movable slide and a die mountable thereon, a die clamp for clamping the die to said slide, said die clamp comprising, a support bracket including a pair of parallel upright bars mounted on said slide, means connecting said bars together, a shaft journalled on said bars, a pair of control arms mounted on and extending from said shaft, a hydraulic cylinder having a cylinder pivotally carried by said bars and a piston rod pivotally connected to said control arms, a pair of eccentrics carried on said shaft and positioned between said bars, said eccentrics being arranged so that a plane extending through the high points thereof and the axis of said shaft aligns with the pivot connection of said piston rod and control arms and said high points are arranged between the axis of said shaft and said pivot connection, a yoke rotatably carried on said eccentrics and normally biased toward said slide, and a clamping bolt adjustably mounted on said yoke and engageable with said die whereby when said bolt is locking said slide and die together actuation of said cylinder in one direction rotates said shaft and eccentrics to move the bolt away from the shaft and initially unlock the clamp and further actuation causes the control arms to abut the yoke and swing the clamping bolt outward away from the die.

3. In a press having a movable slide and a die mountable thereon, a die clamp for clamping the die to said slide, said die clamp comprising, a support bracket including a pair of parallel bars mounted on said slide, a shaft journalled on said bars, at least one control arm mounted on and extending from said shaft, a hydraulic cylinder having a piston rod pivotally connected to said control arm, an eccentric carried on said shaft and positioned between said bars, said eccentric being oriented relative to the pivot connection of said piston rod and control arm so that the high point thereof is positioned on the side of a plane facing said pivot connection wherein said plane extends axially through the axis of said shaft and normal to a plane extending through the axis of said shaft and said pivot connection, a clamping bolt having a strap on one end thereof carried by said eccentric and lockably engageable with said die whereby when said bolt is locking said slide and die together actuation of said cylinder in one direction rotates said shaft and eccentric to move the bolt away from the shaft and initially unlock the clamp and further actuation causes the control arm to swing the clamping bolt outward from the die, and means for normally biasing said clamping bolt into engagement with said slide.

References Cited in the ile of this patent UNITED STATES PATENTS 398,549 Smith Feb. 26, 1889 1,038,624 Messick Sept. 17, 1912 1,395,708 Grode Nov. 1, 1921 1,500,261 Page July 8, 1924 1,929,761 Thwaits Oct. 10, 1933 2,365,151 Solomon Dec. 19, 1944 2,378,653 Pekny June 19, 1945 2,388,546 Jackson Nov. 6, 1945 2,568,905 Wiehsner Sept. 25, 1951 '2,645,506 Sturgis July 14, 1953 2,701,666 Hicks Feb. 8, 1955 2,734,824 De Luca Feb. 14, 1956 2,755,758 Johansen July 24, 1956 2,802,385 Schmidt Aug. 13, 1957 2,834,504 Annicq May 13, 1958 FOREIGN PATENTS 728,543 France July 7. 1932 

